Endoglin Promotes Myofibroblast Differentiation and Extracellular Matrix Production in Diabetic Nephropathy

Diabetic nephropathy (DN) is a complication of diabetes mellitus that can lead to proteinuria and a progressive decline in renal function. Endoglin, a co-receptor of TGF-β, is known primarily for regulating endothelial cell function; however, endoglin is also associated with hepatic, cardiac, and intestinal fibrosis. This study investigates whether endoglin contributes to the development of interstitial fibrosis in DN. Kidney autopsy material from 80 diabetic patients was stained for endoglin and Sirius Red and scored semi-quantitatively. Interstitial endoglin expression was increased in samples with DN and was correlated with Sirius Red staining (p < 0.001). Endoglin expression was also correlated with reduced eGFR (p = 0.001), increased creatinine (p < 0.01), increased systolic blood pressure (p < 0.05), hypertension (p < 0.05), and higher IFTA scores (p < 0.001). Biopsy samples from DN patients were also co-immunostained for endoglin together with CD31, CD68, vimentin, or α-SMA Endoglin co-localized with both the endothelial marker CD31 and the myofibroblast marker α-SMA. Finally, we used shRNA to knockdown endoglin expression in a human kidney fibroblast cell line. We found that TGF-β1 stimulation upregulated SERPINE1, CTGF, and ACTA2 mRNA and α-SMA protein, and that these effects were significantly reduced in fibroblasts after endoglin knockdown. Taken together, these data suggest that endoglin plays a role in the pathogenesis of interstitial fibrosis in DN.

Pomolic Acid Ameliorates Fibroblast Activation and Renal Interstitial Fibrosis through Inhibition of SMAD-STAT Signaling Pathways

Fibrosis is a common pathological feature in most kinds of chronic kidney disease. Transforming growth factor β1 (TGF-β1) signaling is the master pathway regulating kidney fibrosis pathogenesis, in which mothers against decapentaplegic homolog 3 (SMAD3) with signal transducer and activator of transcription 3 (STAT3) act as the integrator of various pro-fibrosis signals. We examine the effects of pomolic acid (PA) on mice with unilateral ureteral obstruction (UUO) and TGF-β1 stimulated kidney fibroblast cells. UUO mice were observed severe tubular atrophy, and tubulointerstitial fibrosis and extracellular matrix (ECM) deposition at seven days postoperatively. However, PA-treated UUO mice demonstrated only moderate injury, minimal fibrosis, and larger reductions in the expression of ECM protein and epithelial-mesenchymal transition (EMT) progress. PA inhibited the SMAD-STAT phosphorylation in UUO mice. PA effects were also confirmed in TGF-β1 stimulated kidney fibroblast cells. In this study, we first demonstrated that PA ameliorates fibroblast activation and renal interstitial fibrosis. Our results indicate that PA may be useful as a potential candidate in the prevention of chronic kidney disease.

SYNTHESIS, CHARACTERIZATION AND ANTIMALARIAL–ANTIMICROBIAL STUDIES OF SOME NOVEL DERIVATIVES OF CHLOROQUINOLINE BASED PYRAZOLES

The prime aim of the present investigation was to synthesize a series of novel derivatives of pyrazole based quinolines by the reaction of substituted chalcones and characterized them by their physical and spectral data. All the compounds were confirmed by TLC and melting point. The structures of the synthesized compounds have been established on the basis of IR, 1 H NMR, EIMS spectral analysis and elemental analysis. The synthesized target compounds were screened for their anti-malarial activity using Vero cell line (C1008; Monkey kidney fibroblast) against Plasmodium falciparum (3D7 strain) with the standard and SI was measured by using IC50 and CC50 of tested compounds. Additionally, the synthesized compounds were evaluated for their in vitro antimicrobial activity against two each gram positive, gram negative and antifungal strains.

A COMPARATIVE ASSESSMENT OF FOLIC ACID-INDUCED CELLULAR SENESCENCE

The biological functions of folic acid (FA) including the prevention of neural tube defects in developing embryos and synthesis of DNA and its repair, have been well reported in literature. As a result; the fortification of folic acid into many daily foods in Canada such as wheat and cereals is mandatory. We have shown that over-osage of FA causes blood haemolysis, leading to progressive anaemia. It is reported that 200 – 400 μg/ml of FA increases the size of blood cells within 2h of treatment, also leading to abnormal cell division and necrosis (in vitro concentrations). This observation suggests early cell senescence. We hypothesized that FA may play a vital role in cellular senescence. 5th generation Kidney fibroblast (COS-7) cells were treated with 200 μg of FA in combination with an anti-neoplastic agent, nocodazole- prior to FA treatment. FA increased the expression of fibronectin (protein marker for aging) of nocodazole treated cells. Furthermore, fibronectin expression was higher in FA-treated cells of the 14th generation compared to the 8th generation. 14th generation cells also showed a larger decrease in cell size when exposed to FA. This suggests FA over-dosage has an affect on the cell growth cycle.